Calibration plate with high-precision and low-cost for visible/infrared camera calibration and calibration method thereof

Abstract

The invention discloses a calibration plate with high-precision and low-cost for visible / infrared camera calibration and a calibration method thereof. The calibration plate comprises a substrate, a spread layer, a transition layer, a heating layer and an insulation layer. The substrate is a rectangular metal plate, the surface of the substrate is treated with black oxidation, and the upper surfaceis coated with a spread layer of the same material as the substrate. The spread layer is processed in accordance with the chess board pattern using a high-precision machine tool. The checkerboard pattern with obvious color contrast can meet the calibration of visible light camera. The transition layer, the heating layer and the insulation layer realize the function of uniformly heating the substrate, and the calibration of the infrared camera can be realized due to the difference in surface emissivity of different regions. The calibration plate has simple manufacturing process, high precisionand low cost, and can be widely used in the field of camera calibration.

Description

technical field [0001] The invention belongs to the field of camera calibration and relates to a high-precision and low-cost calibration plate and a calibration method suitable for calibration of visible light / infrared cameras. Background technique [0002] In the field of camera calibration, calibration techniques can be roughly divided into three types: traditional calibration methods, active vision-based methods, and self-calibration methods. Traditional calibration methods need to use standard reference objects or calibration templates, that is, use the correspondence between feature points on the reference objects or calibration templates and their corresponding camera imaging points to determine camera model parameters. The most famous one is the "camera calibration method based on plane template" proposed by Zhang Zhengyou, which is widely used because of its convenient measurement and high precision. Therefore, when designing the calibration plate, it is necessary n...

AI Technical Summary

Problems solved by technology

For the spatial layered structure design, the heat source is mostly a plane heat source, the target pattern is engraved on a structural plate with a certain thickness, and the target pattern and the heat source are arranged in parallel with a certain distance; The target pattern blocks the infrared light emitted by the light source to realize the feature points, but because there is a certain distance level between the heat source and the pattern, the position of the feature points collected by the camera is deviated; the parallel distance between the target pattern and the heat source is greater. The thinner the near and target pattern plate, the smaller the deviation; but at the same time, the smaller the thickness of the target pattern plate, the lower the structural accuracy

For the attached structure design, multiple regular-shaped sheet heat sources are attached to the response position of the visible light checkerboard target to form an infrared characteristic area. This structure effectively reduces the parallel distance between the target pattern and the heat source. However, since the heat source is attached to the visible light checkerboard target, resulting in thermal diffusion, the boundary of the feature area collected by the infrared camera is blurred, and it is difficult to obtain the precise position of the feature point

For the design of infrared suppression coating, it is mainly to apply regular shaped infrared suppression coating on the surface of the planar heat source to form a regular target pattern; however, to achieve a regular target pattern, the application process of infrared suppression coating has been proposed. Higher difficulty, so the production cost of this calibration board is higher

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